#include <stdio.h>

int main () {
	int n;
	long long int NUM, S1 = 0, S2 = 0, i = 0, j = 0;
	scanf("%d", &n);
	if (n < 3) {
		S2 = 0;
	} else {
		for (j = 1; j <= n - 2; j++) {
			for (i = 1; i <= j; i++) {
				NUM = i * (i + 1) * (i + 2);
				S1 += NUM;
			}
			S2 += S1;
			S1 = 0;
		}
	}
	printf("%lld\n", S2);

	return 0;
}